Data collection -- #2

31/7/13

Before we continue, we have to prove that the electricity is generated by bacteria only, thus we came up with the null hypothesis: "The LB broth does not generate electricity".

In the setup, we replaced the bacteria with LB broth, and our results are as shown:

Copper:

Fig. 19

Fig. 20

Thus this proves that our null hypothesis is true, and that the electricity generated is generated by the bacteria only.

Next, we moved on to testing out how aluminium affects the generation of electricity:

Fig. 21

Fig. 22

As can be seen from Fig. 22, using an aluminum electrode increases the amount of electricity generated by the bacteria.

Fig. 23

Fig. 24

Fig. 25

Fig. 26

As compared with copper:

Fig. 27

Fig. 28

Fig. 29

Fig. 30

Fig. 31

Fig. 32

We can see, from the data collected, that the aluminum electrodes caused the bacteria to generate more electricity than the copper ones. 

Data collection -- #1

24/7/13

After testing out the different metals and their effects on the rate of the generation of electricity with the E. coli (K-12) strain, we started collecting data.

The data for the Zinc electrodes are as shown below:

Fig. 17

Fig. 18

After looking through the data collected, we found that there was a very big fluctuation in the electricity generated (refer to fig. 17). Upon closer research, we found out that zinc was not a good conductor of electricity, thus we had to scrap the idea of having zinc as one of the test metals.

We decided to change the second metal to Aluminium as it is a good conductor of electricity, and it proved to be even better than Copper (refer to following post).